Sure, Intel didn't have any serious patents on the 8080 but they did copyright the assembly language mnemonics. So the Z80 was 100% compatible at the binary lev

Sure, Intel didn't have any serious patents on the 8080 but they did copyright the assembly language mnemonics. So the Z80 was 100% compatible at the binary level but had to use other names for the instructions. Same thing with trademarks. What I was saying is that what is described in the patent text can be freely used after the patent expires.